Boat lift and design

ABSTRACT

A boat lift includes two support beams, each beam having each having a rectangular interior space, the top surface of each beam extending beyond the rectangle to provide a flange for connecting components to the support beam; a hydraulic cylinder assembly positioned within the interior of each support beam and including a base and a piston; a fixed pulley block connected to the base and a moveable pulley block attached to the piston; a bunk for supporting a boat, the bunk supported by the two support beams; and two cables extending from opposing ends each of the support beams. The boat lift does not require overhead supports.

RELATED APPLICATIONS

This application claims priority from U.S. Prov. Pat. App. No. 62/204,355 filed Aug. 12, 2015.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to vehicle lifts, and more particularly to a mechanism for lifting boats.

BACKGROUND OF THE INVENTION

The cleaning, repairing and storing of a boat is most effectively performed by lifting the boat out of the water. To this end, boat lifts have been valuable and widely used. However, they tend to be unsightly, unstable and functionally inefficient.

A typical boat lift employs several pulleys and cables mounted overhead the boat, with the lifting mechanism (cable drive system) in an attic or upper part of an overhead dock or vertical beam structure. In these systems, cables extend from the overhead drive mechanism down to the boat support structure in the water. Not only are the cables unsightly, but so are the drive mechanisms; if they are not hidden in an overhead attic, they are mounted in plain view to a vertical beam structure or on a boat walkway. In addition, they are unstable because the cable lengths from the overhead system to the boat remain long, so that the boat tends to swing and sway in the wind particularly with the boat out of the water and in a raised position on the lift. Further, because of their structural designs, typical boat lifts are not able to provide lifting force proportional to the balanced weight of the lifted boat and so the boat may rise unevenly.

Examples of such boat lifts are shown in the figures; an overhead boat house lift is shown in FIG. 1 and a 4 (four) point boat lift is shown in FIG. 2. As shown in FIG. 1, an overhead boathouse lift 100 includes pulleys 102 that mount to the joists 104 or I-beams of an existing boathouse and utilize either a plurality of slings 106 or a cradle to support the boat to lift it out of the water. A cable drive system 108 is mounted to the upper part of the boathouse. Cables are routed across the upper part of the boathouse from the drive system 108 above the boat, to pulleys 102 on or beyond the width of the boat, and finally down to the supporting sling 106 or cradle.

FIG. 2 shows a 4 point lift 200 to include 4 (four) vertical beam structures placed near the sides of a boat dock, typically on existing wooden pilings 202 used for supporting a walkway 206. In some cases, as is the case shown in FIG. 2, the horizontal beam structures are omitted in favor of the support offered by the wooden pilings 202 themselves. Horizontal beams 204 rest on, or are mounted to, the vertical beam structures or wooden pilings 202, providing a fixed point for attaching cables 208. Vertical bumper guards are sometimes required with a 4 point lift to prevent damage to the boat or fixed structures when the boat “swings” in response to windy conditions. Cable drive systems 212 are mounted on top of pilings 202 on each side of the boat for the purpose of providing even lifting of the boat. Freestanding lifts are similar to the 4 point lift, where the vertical beams themselves rest on the bottom of the lake and reach from below the water line to above the boat hull.

A common complaint of these boat lifts is that the cables and drive system components are unsightly. In the arrangements stated above, the lifting mechanisms (i.e. cable drive systems) are attached far above the boat. The cables extend from the overhead drive systems down to the boat support structure in or near the surface of the water when the boat lifts are in a lowered position and remain visible even with the boat in a raised or lifted position on the boat lift. In the case of the boathouse lift of FIG. 1, the cable drive system 108 is attached to a joist 104 of the boathouse superstructure directly above the boat, and cables are clearly seen extending downward from the roof of the boathouse. Drive systems 212 of the 4 point boat lift of FIG. 2 are shrouded by a cover, but are still clearly visible in that their locations are not hidden from sight. Cables 208 are also clearly visible in either a lowered position or a lifted position.

Another disadvantage of prior art boat lifts is that they are unstable because the lifted boats tend to swing and sway in the wind due to the long cable length remaining between fixed points on the boat lift, even with the boat in a lifted position. Even in a lifted position, cables 110 of FIG. 1 extend from pulleys or rollers 102 mounted on the roof of the boathouse superstructure. The pulleys 102 act as a pivot point with the weight of the boat in the straps 106, creating a literal “swing” as the boat is in a lifted position. The 4 point boat lift of FIG. 2 is in a lifted position and cables 208 are long and easily seen and having an upper pivot point by their connection to the horizontal arms 204, again leading to a swing-like assembly

U.S. Pat. Pub. 2010/0239371, which is hereby incorporated by reference, describes a Boat Lift having a support beam upon which the weight of a boat rests and within which a cable drive system are mounted. The cable drive system draws the support cables into the interior of the support beams to lift the boat toward the point to which the lift cables are fixed. The system of U.S. Pat. Pub. 2010/0239371 is complex, which increases construction cost.

FIGS. 3A, 3B, 4A, and 4B are from U.S. Pat. Pub. 2010/0239371. Referring to FIG. 3A, a boat lift 300 embodying the present invention is shown to generally include a support beam body 302, out of which cables 306 (external lengths shown only) extend to attach at their external ends to elevated fixed points 330 so that when the external cable lengths are shortened, the support beam body 302 and all attached components are raised up to a position shown by FIG. 3B. In the embodiment depicted in FIG. 3A and FIG. 3B, the fixed point 330 to which the external ends of the cables 306 attach are located on stationary posts 322, the cables being held in place by a wedge socket assembly 308. The support beams 302, as well as other components of the present invention, may preferably be made of aluminum or stainless steel to resist corrosion.

Discussed in greater detail below, additional components may be preferred to aid in the operation of lifting a supported vehicle. Such additional components may include adjustable extension members 304 (described in greater detail below) which, in the embodiment of FIG. 3A, telescope into the interior of the support beam body 302 to adjust for a particular width defined by the distance between stationary structures such as posts 322 on either side of the support beam 302, or by the width of the vehicle to be supported on the support beam 302. In other words, the width defined by the cables 306 that extend from the support beam assembly to the elevated fixed points 330 is preferably greater than or at least the width of the boat to be supported by the boat lift 300.

Another additional component may include a perforated bar for easily attaching other components. For example, the support beam 302 is adapted for supporting the weight of a boat and preferably has a perforated bar 318 attached to its upper surface to allow the convenient attaching of hull skid supports 316 which are to contact the hull of the boat. One of ordinary skill in the art will appreciate that a perforated bar allows fasteners such as bolts and the like to attach other components that have corresponding holes such that the fastener aligns through both the holes of the perforated bar and the holes of the other component to matingly engage them.

The support beam is raised and lowered by a cable drive mechanism or system that withdraws cables 306 into the interior of the support beam 302. To this end, components such as pulley bearing assemblies 320 located at both ends of the support beam body 302 mounted on the extension members 304 are preferred to assist the cables in retracting and extending with minimal friction. A power unit 312, preferably a positive displacement hydraulic pump, supplies hydraulic fluid to cable drive components inside the support beam 302 of the cable drive system through hydraulic line 314. The power unit may be placed in a myriad of locations where one of ordinary skill in the art would find readily suitable. As shown in FIG. 3A, for example, the power unit 312 is placed upon a walkway 324. Other preferred locations may include more clandestine locations, such as beneath the walkway. The support beam 302 is shown as having a generally square-shaped and elongated cross section. Other shapes of elongated support beams including, for example, those with cross sections which are round or cylindrically-shaped are considered within the scope of a support beam usable with this and other embodiments. Whether square, cylindrical, or any other shape, those support beams which include an enclosed interior are termed “tubular” herein. Additionally, other preferred shapes of support beams may include “I-beams” or the like which do not have an enclosed interior, but generally have an “I” shaped or “T” shaped cross section, for example, and are also considered within the scope of the present application. In these latter shaped embodiments of support beams, the drive components attached to the support beam on any suitable surface of the support beam, albeit not within an interior.

Two or more support beams may be employed in a boat lift system for more evenly supporting the weight of an elongated vehicle such as a boat. The support beam positions are adjustable along the length of the particular boat upon installation because they tend to behave as separate lifting units and can be placed where needed. A typical preferred support beam assembly (a single support beam) has a capacity of about 5,000 lbs. (more typically 4,000-5,000 lbs.). In order to support more weight, one or more additional support beam assemblies may be added to the boat lift system. For example, if a user was required to lift a 20,000 lbs. boat, 4 standard beams could be used. If after installation of the boat lift, more lifting capacity is required, a user could add one or more support beam assemblies to the existing boat lift without needing to tear out the existing lift and install a completely new lift. The user only need connect the new support beam assembly to the power (hydraulic) supply and the external ends of the cables to fixed points as done with the other support beam assemblies.

The mounting point of the cable to an external, fixed point may be nearly anywhere above the vehicle to be lifted, whether it is in a visible location or a hidden one. It is preferable that, to provide an extra measure of cleanliness to the installation of the boat lift of the present invention, the cable be mounted in a less-observable location, such as beneath a walkway or boat dock structure, such as is shown in FIG. 4A and 4B. Whereas the boat lift 300 of FIG. 4A is shown in a lowered position for accepting a boat upon its hull skid supports 316, FIG. 4B shows the support beam 302 in a raised or lifted configuration for lifting the supported boat above the water line 326. In this raised position, the boat lift 300 is more stable in comparison to the raised position of prior art boat lifts because the minimal slack permitted by the short cable length between cable pivot points 330 reduces the propensity for swinging commonly noted in prior art boat lifts. Additionally, because very little cable length is observable in the raised position, a cleaner aesthetic appearance is achieved. Further adding to the clean appearance, the mounting bracket, post structure or any other suitable mounting point for the cable can be very low profile, as opposed to prior art boat lifts that typically require fixed cable mounting points or pillars that extend far above the water line, as shown in as shown in FIGS. 1 and 2.

Further, because of their structural designs, typical boat lifts are not able to provide lifting force proportional to the balanced weight of the lifted boat and the boat may lift unevenly.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an improved boat lift.

The boat lift includes two support beams, each beam having each having a rectangular interior space, the top surface of each beam extending beyond the rectangle to provide a flange for connecting components to the support beam; a hydraulic cylinder assembly positioned within the interior of each support beam and including a base and a piston; a fixed pulley block connected to the base and a moveable pulley block attached to the piston; a bunk for supporting a boat, the bunk supported by the two support beams; and two cables extending from opposing ends each of the support beams.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more thorough understanding of the present invention, and advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows an isometric view of boathouse boat lift;

FIG. 2 shows an isometric view of a 4(four) point boat lift;

FIG. 3A shows an isometric view preferred embodiment of the boat lift of the present invention in a lowered position;

FIG. 3B shows the boat lift of FIG. 3A in a lifted position;

FIG. 4A and 4B show the position of the lifts of FIG. 3A and FIG. 3B respectively, and additionally show a more clandestine placement of the cable mounting points;

FIG. 5 shows an embodiment of the boat lift using two cable drive systems;

FIG. 6 shows multiple views of a preferred support beam;

FIG. 7A shows a support beam assembly with end caps, piston assembly, and end channel pulley support assembly;

FIG. 7B shows an end cap;

FIG. 8 shows an end cap;

FIG. 9 shows a piston assembly including a cylinder body to which pulley assemblies are attached;

FIG. 10 is a photograph of a pulley block showing the insertion of the cables;

FIG. 11 shows a pulley block end plate;

FIG. 12 shows details of pulley assembly;

FIG. 13 shows a channel pulley support assembly;

FIG. 14 shows a pulley block assembly;

FIGS. 15A and 15B shows a support beam assembly with a cable extending from a pulley block assembly;

FIG. 16 shows a bottom view of a piston assembly with pulley block assembly mounted and a cable extending therefrom;

FIGS. 17A and 17B show a stand alone boat dock;

FIGS. 18A and 18B show schematically the cable routing;

FIG. 19 is a first pictorial view of a support beam for a boat lift including a cylinder, rod, and pulley assembly according to one embodiment of the present design;

FIG. 20 is a second pictorial view of the support beam of FIG. 19;

FIG. 21 is the pictorial view of the support beam of FIG. 20 including the hidden components of the cylinder, rod, and pulley assembly by the support beam in dotted lines;

FIG. 22 is a bottom elevational view of the support beam of FIG. 19;

FIG. 23 is a second bottom elevational view of the support beam of FIG. 19;

FIG. 24 is a third bottom elevational view of the support beam of FIG. 19;

FIG. 25 is an elevated view of the support beam of FIG. 19 without the cylinder, rod, and pulley assembly components shown in FIGS. 19-24;

FIG. 26 is a second elevated view of the support beam of FIG. 25;

FIG. 27A is a bottom plan view of the support beam of FIG. 25;

FIG. 27B is a top plan view of the support beam of FIG. 25;

FIG. 28A is a right plan view of the support beam of FIG. 25;

FIG. 28B is a left plan view of the support beam of FIG. 25;

FIG. 29 is a pictorial view of a stand alone boat lift according to one embodiment of the present design showing a boat in dashed lines, the boat being part of the environment in which the design is used and not being part of the claimed design;

FIG. 30 is a pictorial view of a boat lift according to one embodiment of the present design;

FIG. 31 is a second pictorial view of the boat lift of FIG. 30;

FIG. 32 is a third pictorial view of the boat lift of FIG. 30;

FIG. 33 is a back plan view of the boat lift of FIG. 30;

FIG. 34 is a front plan view of the boat lift of FIG. 30;

FIG. 35 is a right plan view of the boat lift of FIG. 30;

FIG. 36 is a left plan view of the boat lift of FIG. 30;

FIG. 37 is a top plan view of the boat lift of FIG. 30;

FIG. 38 is a bottom plan view of the boat lift of FIG. 30;

FIG. 39 is a top view of an end cap for support beam for a boat lift;

FIG. 40 is a rear view of an end cap for support beam for a boat lift;

FIG. 41 is a bottom view of an end cap for support beam for a boat lift;

FIG. 42 is a right side view of an end cap for support beam for a boat lift;

FIG. 43 is a pictorial view of an end cap for support beam for a boat lift;

FIG. 44 is a left side view of an end cap for support beam for a boat lift; and

FIG. 45 is a front view of an end cap for support beam for a boat lift.

The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In accordance with at least one embodiment of the present invention, the problems of unsightliness, instability and functional inefficiency are solved by placing the components of a lift mechanism within the interior of hollow support beams upon which the weight of the boat rests, and providing lifting force by withdrawing support cables to within the hollow support beams, the external ends of the cables attached to fixed points.

In this way, the embodiment provides a cleaner, more aesthetically pleasing structure because as the boat is in a lifted position, the support cables are nearly unseen, as are the drive system components. Further, it provides more stability, because in a lifted configuration, less cable length exists between attachment or contact points, reducing a “swinging” effect most notably observed in prior art boat lifts. Still further, it provides a more self-contained and inclusive support and cable drive mechanism assembly, allowing more versatility in positioning the support beams, and thus, the lifting force.

A boat lift embodying the present invention generally includes a support beam member with a cable drive system preferably placed inside the support beam. The cable drive system provides lifting force by engendering vertical motion of the support beam to which it is attached. Because the drive components are within the support beam used to lift up a boat, the drive components function under water. In the preferred embodiments shown in the figures and described below, cable drive systems generally operate by withdrawing cable length within or along the body of the support beam, thereby shortening the length of the cable extending beyond the body of the support beam. Because the exterior cable ends are attached to a fixed point, such as a dock or stationary post, the reduction in cable length outside the support beam causes the support beam to be pulled up toward the fixed point of the attached cable drive system, thus raising any structure being supported by the support beam (e.g. a boat).

FIG. 5 shows an embodiment of a boat lift 500 including two support beams 602 (one shown partly transparent) with a cable drive system 504 placed inside each of the support beams (shown only in one beam). In some of the embodiments, the length of the support beam is not adjustable which simplifies the construction. In such embodiments, the beam is cut to the desired length before assembly. Bunks 506, which support a boat hull (not shown) are mounted, on support beams 602. Cables 508 extend vertically from the ends of support beams 602 and are attached to fixed attachment points, such a points on a boat dock or on a frame. As cable drive systems 504 take up cable within support beams 602, the boat lift assembly 500 moves upward. Additional support beams can be used for heavier boats.

FIG. 6 shows multiple views of a preferred support beam. The support beam 602 is shown as having a generally rectangular shape with the top and bottom surfaces 604 and 606 extending beyond the vertical walls to produce flanges 608. The flanges of the support beam allow fasteners such as bolts and the like to attach other components, such as the bunks, to the support beam without the bolts interfering with the cables inside the support beams. That is, the preferred support beam is shaped like two I-beams together, “II”, forming a passage in the interior center. Other beam shapes, such as a beam forming a channel with flanges only on the top surface, may be used. The interior is typically not sealed on the ends, allowing water into the interior, although end caps may be used to keep out debris. FIG. 7A shows the beam 602 with end caps 702, piston assembly 704, and end channel pulley support assembly 1302. FIG. 7B shows an end cap 702.

The piston assembly 704 is fixed inside support beam 602 (piston assembly 704 is shown outside the beam in FIG. 7 prior to assembly) to one end of the support beam, while the other end of the piston assembly mores longitudinally within the support beam to change the length of cable extending out from the inside of the support beam to lift or lower the boat.

End caps 702 can be mounted onto one or both ends of the support beam (depicted in FIGS. 301-307) to prevent debris from entering the interior of beam 602. The end caps are preferably removable from the support beam in order to access the internal components of the support beam, such as the piston assembly and cables.

FIG. 8 shows an end cap 702. The end cap 702 includes a groove 802 which allows the cable to enter and exit the support beam as seen in FIG. 5. The end caps preferably prevent debris, such as dirt, leaves, and other objects, from entering the support beam. Part of the end cap 702 fits within the end of beam 602 and is retained by a friction fit. Other styles of end caps may be used.

The cable drive system generally operates by withdrawing cable length into the body of the support beam, thereby shortening the length of the cable extending beyond the body of the support beam to the fixed support point. Because the exterior cable ends are attached to a fixed support point, such as a dock or stationary post, the reduction in cable length outside the support beam causes the support beam to be pulled up toward the fixed point of the attached cable drive system, thus raising any structure being supported by the support beam (e.g. a boat).

The support beam is raised and lowered by a cable drive mechanism or system that withdraws cables into the interior of the support beam. FIG. 9 shows a piston assembly 704 including a cylinder body 902 to which pulley assemblies 904 and 906 are attached. A single bolt 912 connects a pulley block 904 to pulley block end plate 916 and to the piston end 908. A single bolt 914 connects second pulley block 906 to a second pulley block end plate 916 to the base of cylinder body 902. Pulley block end plate 916 is shown in more detail in FIG. 11. Pulley assemblies 904 and 906 are shown in more detail in FIG. 14 which show a pulley housing 1402, pulleys 1404, axle 1406, and rods 1408 that retain the cables within the pulleys if slack develops in the cables. Pulley assemblies 904 and 906 can be identical, although pulley assembly 904 does not need holes for terminating the cables. Similarly, plates 910 and 916 can be identical, although plate 910 does not require holes for terminating the cables.

A holding valve built into the base of the cylinder body 902 keeps the cylinder from leaking under load. If hydraulic pressure is released by a malfunction of the cylinder, the holding valve will keep the boat lift from dropping. Two cables are used with each piston assembly 704 to lift the support beam. One end of each cable is preferably fixed on base end of the piston assembly 704 with the other end of each cable being fixed to the dock or other fixed support that supports the boat lift during lifting. FIG. 11 shows details of pulley block end plate 916 and FIG. 12 shows details of pulley assembly 906. The pulley assembly 906 each includes three holes in the base, which holes align with holes in the pulley block end plate 916. The center holes 1102 and 1202 accommodates the bolt that secures the pulley block end plate 916 and pulley assembly 906 to the cylinder body 902.

The holes 1104 and 1106 in pulley block end plate 916 and holes 1204 and 1206 in the pulley assembly 906 accommodate the cables as shown in FIG. 10. The hole 1104 in pulley block end plate 916 and hole 1204 in the pulley assembly 906 are aligned, but have different diameters. Similarly, hole 1106 in pulley block end plate 916 and hole 1206 in the pulley assembly 906 are aligned, but have different diameters. The cables are terminated with a compression sleeve or other device having a diameter greater than the diameter of the smaller of the smaller of the two aligned holes (1104 or 1204; 1106 or 1206) and smaller than the larger of the two holes (1104 or 1204; 1106 or 1206). Thus, the cable can be inserted into the aligned holes, but the compression sleeve will prevent the cable from being pulled all the way through. The larger diameter hole provides a depression analogous to a counter bore which allows the compression sleeve to be positioned out of the way of the pulleys. For the cable having the compression sleeve on the outside of the pulley assembly 906, this feature is less important because the compression sleeve is not in the way of the pulley. The cables could be retained in the pulley block by various known means, but it is preferred that the cables extend in opposite directions from their anchor points in the pulley housing. The invention also includes a method of raising a boat out partly or completely of the water using the systems described herein.

Applicant has found that it is difficult to raise the boat lift while maintaining the lift level. Applicant has found that the cable configuration described herein allows the lift to be raised without while remaining level. As shown in FIG. 10, the cables extend in opposite directions from pulley block end plate 916, one of the cables going into the pulley assembly 906 and the other cable going away from pulley assembly 906 and toward pulley assembly 904 positioned on the piston end 914. Each of the cables wraps around a corresponding first pulley on the pulley block to which it is directed, then circles back around the opposite pulley block. Each cable then makes another circuit so that it engages two pulleys on each end of the piston assembly. After engaging the two pulleys, each cable is directed to a center pulley. As shown in FIGS. 15A and 15B, pulley assembly 906 extends slightly beyond support beam 602, so that the center pulley of pulley assembly 906 can change the direction of the cable and the cable can extend vertically from pulley assembly 906 without hitting support beam 602. A rod 1502 serves to maintain cable 508 in the pulleys if slack were to develop in the cable. FIG. 16 shows a bottom view of the pulley block assembly with the cables installed. The single cable extending from the pulley block assembly would extend upward to the fixed support point.

FIGS. 18A and 18B show schematically the cable routing. Both cables 1802 and 1804 run back and forth between pulleys on a fixed pulley assembly 1806 and pulleys on a moveable pulley assembly 1808. Both cables are anchored near fixed pulley assembly 1806. Cable 1802 and 1804 leave the anchor going in opposite directions. For example, cable 1802 leaves the anchor at the fixed pulley assembly and runs to a pulley on the moveable piston assembly. Cable 1802 runs back to a pulley on the fixed pulley assembly, back to a pulley on the moveable pulley assembly and back to a pulley on the fixed pulley assembly. The cable then runs over and past a pulley on the moveable pulley assembly without changing direction. Cable 1802 continues to a fixed pulley at the end of the support beam, which changes the direction of the cable 1802 to vertical and cable 1802 continues to a fixed point on the dock.

Cable 1804 extends from anchor 1810 to a pulley on the fixed pulley block assembly 1806, then to a pulley on the moveable pulley block assembly. Cable 1804 runs back to a pulley on the fixed cable block assembly and back again to a pulley on the moveable pulley block assembly and back to a pulley on the fixed pulley block which changes the direction of the cable to vertical and cable 1804 continues to a fixed point on the dock. As shown in FIGS. 18A and 18B, there are five pulleys on the fixed pulley block assembly and five pulleys on the moveable pulley block assembly. FIG. 18A shows that cable 1802 is longer than cable 1804.

The cable in the opposite direction that leaves pulley assembly 904 and is guided by the center pulley on the piston end pulley assembly 904 without changing direction. The cable continues to an end channel pulley support assembly 1302 (FIG. 13 shows) that is mounted at the end of support beam 602 (FIG. 7) opposite to the end at which the cylinder base is attached. End channel pulley support assembly 1302 includes a support structure 1304 a and 1304 b that attach to support beam 602 and supports an axle 1306 that supports a pulley 1308 changes the direction of the cable 90 degrees so that the cable extends vertically from support beam 602 to a fixed support such as a boat dock of a frame. The two cables are of different lengths because of the additional distance that the cable must traverse between pulley block 904 and pulley 1308.

Thus, in a preferred embodiment, the hydraulic cylinder is contained with the support beam, which has a fixed, not adjustable, length. The piston assembly 704 includes a cylinder body having a based that is fixed at one end of the support beam and a piston that moves within the support beam. A first pulley block is fixed to the cylinder base and extend slightly from the support beam 602 so that the point at which the cable separates from the pulley is outside the support beam to allow the cable to leave the support beam in a vertical direction. A second pulley block positioned on the end of the movable piston and the cable leave the second pulley block without changing direction and is guided by the center pulley toward end channel pulley support assembly 1302 where the cable changes direction and leaves the support beam in a vertical direction.

Applicant has found that the boat lift rises uniformly when both cables terminate at the same pulley block, preferably the fixed pulley block, and the cables extend from their terminations in the pulley block in opposite directions. That is, the cables enter into holes in the pulley block from opposite directions and the ends are terminated on opposite sides of the pulley block wall.

Skilled persons will understand the number of pulleys can vary to alter the ration of the travel distance of the pulley to the vertical travel distance of the boat lift. Applicants have found that having 5 pulleys on each end of the piston assembly provides sufficient movement of the boat lift while allowing use of a hydraulic piston that provides sufficient force yet can fit within the support beam.

A power unit, preferably a positive displacement hydraulic pump, supplies hydraulic fluid to cable drive components inside the support beam of the cable drive system through a hydraulic line. The power unit may be placed in a myriad of locations where one of ordinary skill in the art would find readily suitable.

FIGS. 17A-B show an embodiment of a stand alone boat lift including support posts, two support beams each including a cylinder, rod, and pulley assembly with cables, and sleeves that fit over the support beams. As the cables are drawn into and out of the pulley assemblies which raise and lower the support beams, respectively, the sleeves over the support beams raise and lower with the support beams. FIG. 17A shows the stand alone boat lift system with a boat depicted in a dotted line, which is not part of the boat lift system. FIG. 17B shows the stand alone boat lift system depicted in FIG. 17A without the boat. A support assembly at 1710 mounted on the end of support beams 1708 includes sleeves 1704 that fit over the posts 1702 and are attached to the support beams 1708. A truss 1706 that moves up and down with the support beams 1708 maintains a fixed distance between posts 1702 and prevents deformation that would interfere with the lifting. A support assembly including sleeve 1704 and bracing attached to the end of the support beam. Cables from the support beams are attached to fixed points on post 1702. The stand-alone boat lift does not rely on a deck or other existing structure to attach the lift cables. The stand-alone boat lift can be positioned on an uneven surface. The bottoms of posts 1702 can be at different height from the water surface. The ability of the sleeves 1704 to slide along the posts 1702 allow the bunk to be leveled, even when the posts rest on surfaces of different heights. The cable lengths between the end of the support beam and the attachment point can be adjusted to accommodate different distances from the support beam to the attachment point on the posts. Each post 1702 can also have multiple cable attachment points to accommodate different cable lengths due to different distances from the ends of the support beam to the bottom of the posts, cause by an uneven surface below the boat lift. This allows the support beams to be configured parallel to the water surface on an uneven bottom surface. That is, on installation, the posts can rest on the bottom while the sleeves can slide on the posts to different positions along the different posts so that the sleeve are in the same plane to level each support beam, and the support beams can be positioned in the same plane to level the bunk.

FIGS. 19 to 28B shows a design for a support beam that can be used with the boat lift described above.

FIG. 19 is a first pictorial view of a support beam for a boat lift including a cylinder, rod, and pulley assembly according to one embodiment of the present design.

FIG. 20 is a second pictorial view of the support beam of FIG. 19.

FIG. 21 is the pictorial view of the support beam of FIG. 20 including the hidden components of the cylinder, rod, and pulley assembly by the support beam in dotted lines.

FIG. 22 is a bottom elevational view of the support beam of FIG. 19.

FIG. 23 is a second bottom elevational view of the support beam of FIG. 19.

FIG. 24 is a third bottom elevational view of the support beam of FIG. 19.

FIG. 25 is an elevated view of the support beam of FIG. 19 without the cylinder, rod, and pulley assembly components shown in FIGS. 19-24.

FIG. 26 is a second elevated view of the support beam of FIG. 25;

FIG. 27A is a bottom plan view of the support beam of FIG. 25.

FIG. 27B is a top plan view of the support beam of FIG. 25.

FIG. 28A is a right plan view of the support beam of FIG. 25.

FIG. 28B is a left plan view of the support beam of FIG. 25.

FIGS. 27A and 27B are opposing sides of the support beam and can therefore be switched depending on the beam's orientation. For example, FIG. 27A can be the top plan view of the support beam while FIG. 27B can be the bottom plan view of the support beam. FIGS. 28A and 28B are opposing sides of the support beam and can therefore be switched depending on the beam's orientation. For example, FIG. 28A can be the left plan view of the support beam while FIG. 28B can be the right plan view of the support beam.

FIGS. 29 to 38 show a design for a stand-alone boat lift that can be used with the boat lift described above.

FIG. 29 is a pictorial view of a stand-alone boat lift according to one embodiment of the present design showing a boat in dashed lines, the boat being part of the environment in which the design is used and not being part of the claimed design.

FIG. 30 is a pictorial view of a boat lift according to one embodiment of the present design.

FIG. 31 is a second pictorial view of the boat lift of FIG. 30.

FIG. 32 is a third pictorial view of the boat lift of FIG. 30.

FIG. 33 is a back plan view of the boat lift of FIG. 30.

FIG. 34 is a front plan view of the boat lift of FIG. 30.

FIG. 35 is a right plan view of the boat lift of FIG. 30.

FIG. 36 is a left plan view of the boat lift of FIG. 30.

FIG. 37 is a top plan view of the boat lift of FIG. 30.

FIG. 38 is a bottom plan view of the boat lift of FIG. 30.

FIGS. 39-45 show a design a for an end cap that can be used with a boat lift.

FIG. 39 is a top view of an end cap for support beam for a boat lift.

FIG. 40 is a rear view of an end cap for support beam for a boat lift.

FIG. 41 is a bottom view of an end cap for support beam for a boat lift.

FIG. 42 is a right side view of an end cap for support beam for a boat lift.

FIG. 43 is a pictorial view of an end cap for support beam for a boat lift.

FIG. 44 is a left side view of an end cap for support beam for a boat lift.

FIG. 45 is a front view of an end cap for support beam for a boat lift.

The broken lines in FIGS. 19-45 form no part of the designs.

The system describes herein provides the boating industry with a dependable solution for lifting a boat out of the water for docking and storage. The invention includes more than one novel and inventive aspect, and not all implementations will require all aspects to be combined in each implementation. Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. The invention is not limited to the use of boats or for the boating industry alone, but is useful in other areas, such as the automotive area, and in any environment where heavy equipment is desired to be moved from one position to another. Details of the boat lift not described in embodiments described herein are described in U.S. Pat. Pub. 2010/0239371.

Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. For example, embodiments of the present invention are shown in the figures to be attached to a walkway or other existing structure. However, it is within the scope of the present invention that the embodiments may also be freestanding, that is, including a structure to mount fixed cable to or modifying an existing element of the embodiments without undue experimentation. Further, one of ordinary skill in the art will appreciate that while embodiments of the present invention are particularly drawn to boat lifts, it is within the scope of the present invention that embodiments are also capable of lifting other vehicles, such as cars, and can be used in other venues such as car garages. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. 

We claim as follows:
 1. A boat lift, comprising: two support beams, each beam having each having a rectangular interior space, the top surface of each beam extending beyond the rectangle to provide a flange for connecting components to the support beam; a hydraulic cylinder assembly positioned within the interior of each support beam and including a base and a piston; a fixed pulley block connected to the base and a moveable pulley block attached to the piston; a bunk for supporting a boat, the bunk supported by the two support beams; and two cables extending from opposing ends each of the support beams, the cables extending in opposite directions from fixed pulley block.
 2. The boat lift of claim 1 further comprising a single pulley positioned at the end of the opposite end of the support beam to the fixed pulley block, the single pulley accepting the cable from the moveable pulley support.
 3. The boat lift of claim 1 in which the bunk is bolted to the flange on the support beam.
 4. The boat lift of claim 1 further comprising a single pulley positioned at the end of the opposite end of the support beam to the fixed pulley block, the single pulley accepting the cable from the moveable pulley support and changing the direction of the cable to extend vertically for securing at a fixed anchor point.
 5. The boat lift of claim 1 in which the fixed pulley block includes 5 pulleys and in which the cable extends vertically from pulley block for securing at a fixed anchor point.
 6. A boat lift, comprising: two support beams, each beam having each having an interior space; each support beam including a hydraulic cylinder assembly positioned within the interior and including a base and a piston; a fixed pulley block connected to the base; a moveable pulley block attached to the piston; and two cables anchored to the fixed pulley block extending from the fixed pulley block in opposite directions, one cable routed from the fixed pulley block to a pulley in the moveable pulley block and the other cable routed from the fixed pulley block to the base.
 7. A stand-alone boat lift having a piston and pulleys in a support beam and sleeve positioned over posts which rest on the surface below the water, the sleeves slidable along the post to level the bunk. 